The pros and cons of circumcision have fueled a heated debate. Now from the World Health Organization comes evidence that is difficult to ignore: Male circumcision could lower female-to-male HIV transmission rates by 50 to 60 percent, according to 2007 results of three clinical trials conducted on more than 10,000 men in Kenya, Uganda, and South Africa. In the wake of these findings, demand for the procedure has surged among African men, overwhelming government hospitals and fueling fears that untrained hucksters offering unsanitary surgery in makeshift clinics could transmit bloodborne diseases through the reuse of nonsterile scalpels. Botched circumcisions can lead to scarring, partial penile amputation, and even death.